I met my first serious girlfriend after my first divorce—yes, there are more of both—through a proto-Facebook created at Google. It was 2004, and it's name was Orkut. But social networks go back to 1995.

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It all started with Classmates.com, which apparently has 50,000,000 users now. On the top of the pyramid is Facebook and its 300 million users, followed by MySpace's 263 million. In the middle you have a huge constellation of sites, most of which I just can't recognize. Trombi? Vampirefreaks? Bigadda? Cafemom? Geni? Itsmy? Qzone? Xanga?